Drugs based on nitroarene, aromatic N-oxide or quinone structures are frequently reduced by cellular reductases to toxic products. Reduction often involves free radicals as intermediates which react rapidly with oxygen to form superoxide radicals, inhibiting drug reduction. The elevation of cellular oxidative stress accompanying oxygen inhibition of reduction is generally less damaging than dru...

Many chemical reactions which are otherwise clean often lead to the formation of multiple products. Such products may be formed due to a lack of chemo-, regio- and/or stereoselectivity. For such reactions to be useful, one should be able to control them to yield a single desired product. Of the many approaches used in this context, the use of reaction media with features different from those of...

Microbial transformation has been successfully applied in the production of steroid intermediates with therapeutic use and commercial value in pharmaceutical industry due to its high regio- and stereo-selectivity. As such, it is still important to screen microbial strains with novel activity or more efficient abilities in the development of the commercial steroid industry. Biotransformation of ...

Carbohydrates and natural products serve essential roles in nature, and also provide core scaffolds for pharmaceutical agents and vaccines. However, the inherent complexity of these molecules imposes significant synthetic hurdles for their selective functionalization and derivatization. Nature has, in part, addressed these issues by employing enzymes that are able to orient and activate substra...

Methods for the determination of Vitamin B12 remain limited due to their low sensitivity and poor selectivity. In the present work, a simple and sensitive HPLC-ESI-MS method for determining Vitamin B12 in food products and in multivitamin-multimineral tablets was developed. Vitamin B12 was extracted from food products with 50 mM sodium acetate buffer (pH 4.0) in the presence of sodium cyanide. ...

The selective α,α-difluorination of carbonyl compounds remains a challenge in modern organic synthesis; current methods often incorporate stepwise processes and/or harsh conditions, providing unsatisfactory mixtures of mono- and difluorinated products. In this communication, a practical, mild, and one-pot method for the selective α,α-difluorination of readily available acid chlorides is reporte...

The two-step electroreduction of CO2 to multi-carbon products with a high selectivity and production rate industrial relevance provides an alternative route for converting fuels chemicals.

The copper-catalyzed diboration of ketones followed by an acid-catalyzed elimination leads to the formation of 1,1-disubstituted and trisubstituted vinyl boronate esters with moderate to good yields and selectivity. Addition of tosic acid to the crude diboration products provides the corresponding vinyl boronate esters upon elimination. The trisubstituted vinyl boronate esters are formed as the...

The choice is yours: a highly stereoselective synthesis of α-alkyl-α-hydroxy-β-amino esters is accomplished through a tandem Wittig-rearrangement/Mannich reaction sequence. Transformations of N-benzyl or N-Boc imines proceed with high selectivity for formation of syn-amino alcohol derivatives, whereas N-Boc-2-(phenylsulfonyl)amines generate anti-amino alcohol products. Auxiliary cleavage (trans...

Proto-boryl additions to 1,1-disubstituted allenes in the presence of 1.0-5.0 mol % of chiral NHC-Cu complexes, B2(pin)2, and t-BuOH proceed to afford alkenyl-B(pin) products in up to 98% yield, >98:2 site selectivity, and 98:2 er. The enantiomerically enriched alkenylboron products can be converted to otherwise difficult-to-access alkenyl bromides, methyl ketones or carboxylic acids. What's mo...